The effect of intra-operative skeletal (skull femoral) traction on apical vertebral rotation.

The study design is a retrospective review of consecutive case series. Our goal was to identify and quantify the effect of skeletal traction on the apical vertebral rotation (AVR). Intra-operative skeletal traction has been used for the correction of large magnitude idiopathic and neuromuscular scoliosis. The ability of skeletal traction to correct the rotational deformity of the spine has not been characterized. Following REB approval, retrospective analysis of 22 (AIS = 14, neuromuscular = 8) consecutive pediatric patients having surgical posterior instrumented correction and fusion for their scoliosis was performed. Intra-operative skeletal traction with approximately 50% body weight was achieved with smooth distal femoral pins. Counter-traction up to 25% was used through Gardner-Wells tongs. The AVR of the major curve was assessed using the Nash-Moe grading system by a radiologist and a senior spine surgeon not involved in the treatment of these cases. Statistical analysis was performed to determine the significance. The overall mean AVR of the major structural curve was 3.1 +/- 0.8 and reduced to 2.4 +/- 0.6 (p = 0.0001) following traction. The AVR decreased by one or more Nash-Moe grades with traction in 14/22 (64%) patients. The Cobb angle corrected from a mean of 88.2 degrees to 49.1 degrees (44.3%, p = 0.00001) with traction. The decrease in AVR correlated with the higher magnitude Cobb angles (correlation 0.53, p = 0.014). Patients with pre-traction AVR > or = 3 showed the largest change with traction (3.4-2.5, p = 0.000004). There was very good association between the radiologist and the spine surgeon, 0.72(standing films) and 0.63(traction films). The minor structural curve corrected from a mean Cobb of 53.5 degrees to 33.8 degrees (37.8%) with AVR decreasing from a mean of 1.9 to 1.4 (p = 0.014). Significant apical derotation occurs with the use of intra-operative skull-skeletal traction in the correction of high magnitude scoliotic curves. This derotation can facilitate spinal exposure, placement of pedicles screws and final correction in these patients.

Posterior column reconstruction with autologous rib graft after en bloc tumor excision.

STUDY DESIGN: Retrospective review of consecutive case series. OBJECTIVE: To evaluate the efficacy of using autologous rib graft for fusion across long posterior column defects. SUMMARY OF BACKGROUND DATA: Achieving fusion across large posterior column defects after en bloc tumor resection can be difficult. Rib graft can be harvested from the local wound, and its shape and structural properties are well suited for reconstruction of thoracic posterior column deficits. METHODS: After Research Ethics Board approval, a retrospective review of the charts of 17 consecutive patients undergoing posterior column reconstruction after en bloc tumor resections was carried out. Autologous vascularized and nonvascularized rib grafts were utilized in 8 and 9 cases, respectively; 14 patients with malignant tumors and 3 with benign etiology. After surgery, patients underwent routine clinical and radiographic follow-up, with a computed tomographic scan performed at a minimum of 6 months in all surviving patients. Clinical and radiographic films were analyzed. RESULTS: Computed tomographic scans at a minimum of 6 months demonstrated graft incorporation in all surviving cases. There was no obvious difference at 6-month imaging to differentiate vascularized from nonvascularized grafts. There were no cases of graft dislodgement or fracture. Graft site morbidity was difficult to isolate from the morbidity of these large procedures. No complications related to the graft were identified. CONCLUSION: The use of autologous rib graft with a proximal step-cut and distal saddle-cut supplemented with posterior instrumentation allowed immediate stabilization of the posterior column defect created by the en bloc tumor resection. This technique of fashioning the graft and taking advantage of its natural curved structure for immediate press-fit was associated with graft incorporation in our cases.

Neurophysiological changes in deformity correction of adolescent idiopathic scoliosis with intraoperative skull-femoral traction.

STUDY DESIGN: Retrospective review of 36 consecutive patients undergoing coronal plane deformity correction with intraoperative skull-femoral traction between 2005 and 2008 with motor evoked potential (MEP)/somatosensory evoked potential monitoring. OBJECTIVE: To determine the prevalence and significance of neurophysiological changes with intraoperative skull-femoral traction in adolescent idiopathic scoliosis. SUMMARY OF BACKGROUND DATA: Intraoperative skeletal traction can be associated with spinal cord stretching and ischemia with resultant electrophysiological changes. The prevalence and risks of such changes and their clinical significance is unknown. METHODS: Thirty-seven procedures involving 36 patients (27 females and 9 males) with a mean age of 14.8 (12-18) years were divided into two groups on the basis of the presence (group 1, n = 18 procedures) or absence (group 2, n = 19) of significant MEP changes with surgery. They were compared with patients undergoing correction without traction (group 3). RESULTS: Significant differences among the groups were observed in mean preoperative Cobb angle (86° vs. 70° vs. 59°), mean intraoperative posttraction Cobb angle (50.0° vs. 34.6°), traction index (0.41 vs. 0.50), flexibility index (0.14 vs. 0.27 vs. 0.25), and presence of primary lumbar curves (0% vs. 32% vs. 14%). Initial onset of MEP amplitude loss (group 1) occurred at a mean of 94 (1-257) minutes from the onset of surgery, was bilateral in 13 procedures, and improved at a mean of 5.5 (1-29) minutes after decreasing or removing the traction. At closure, complete bilateral recovery to baseline was observed in 10 procedures, recovery to >50% baseline in five, and recovery to <50% baseline in three procedures. There were no neurologic deficits in this series. CONCLUSION: Intraoperative traction is associated with frequent changes in MEP monitoring. The thoracic location of the major curve, increasing Cobb angle, and rigidity of major curve are significant risk factors for changes in MEP with traction. The presence of any MEP recordings irrespective of its amplitude at closure was associated with normal neurological function. Somatosensory evoked potential monitoring did not correlate with the traction induced MEP amplitude changes.

Lumbar vertebral hemangioma causing cauda equina syndrome: a case report.

STUDY DESIGN: Case report. OBJECTIVES: To report a case of lumbar hemangioma causing neurogenic claudication and early cauda equina, managed with hemostatic vertebroplasty and posterior decompression. SUMMARY OF BACKGROUND DATA: This is the first report to our knowledge of a lumbar hemangioma causing neurogenic claudication and early cauda equina syndrome. Most hemangiomas causing neurologic symptoms occur in thoracic spine and cause spinal cord compression. Vertebroplasty as a method of hemostasis and for providing mechanical stability in this situation has not been discussed previously in the literature. METHODS: L4 hemangioma was diagnosed in a 64-year-old woman with severe neurogenic claudication and early cauda equina syndrome. Preoperative angiograms showed no embolizable vessels. Posterior decompression was performed followed by bilateral transpedicular vertebroplasty. The patient received postoperative radiation to prevent recurrence. RESULTS: Complete relief of neurogenic claudication and cauda equina with less than 100 mL of blood loss. CONCLUSION: A lumbar hemangioma of the vertebral body, although rare, can cause neurogenic claudication and cauda equina syndrome. Intraoperative vertebroplasty can be an effective method of hemostasis and provide stability of the vertebra following posterior decompression.